/**
 * 
 */
package com.utils.base64;

import java.io.UnsupportedEncodingException;

/**
 * @version 1.0.0 创建时间：2013-9-14 下午4:17:34 Base64转换器
 * 将'+' --> '<' 并去除换行
 */
public class Base64Converter extends Base64{
	
	
    /**
     * 字符表（'+' --> '<'）
     */
    private static char[] codec_table = { 'A', 'B', 'C', 'D', 'E', 'F', 'G',  
        'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',  
        'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g',  
        'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',  
        'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6',  
        '7', '8', '9', '<', '/' };
    
    
    public static String encodeWithNoDLE(byte[] a) {  
        int totalBits = a.length * 8;  
        int nn = totalBits % 6;  
        int curPos = 0;// process bits  
        StringBuffer toReturn = new StringBuffer();  
        while (curPos < totalBits) {  
            int bytePos = curPos / 8;  
            switch (curPos % 8) {  
            case 0:  
                toReturn.append(codec_table[(a[bytePos] & 0xfc) >> 2]);  
                break;  
            case 2:  
  
                toReturn.append(codec_table[(a[bytePos] & 0x3f)]);  
                break;  
            case 4:  
                if (bytePos == a.length - 1) {  
                    toReturn  
                            .append(codec_table[((a[bytePos] & 0x0f) << 2) & 0x3f]);  
                } else {  
                    int pos = (((a[bytePos] & 0x0f) << 2) | ((a[bytePos + 1] & 0xc0) >> 6)) & 0x3f;  
                    toReturn.append(codec_table[pos]);  
                }  
                break;  
                case 6:  
                if (bytePos == a.length - 1) {  
                    toReturn  
                            .append(codec_table[((a[bytePos] & 0x03) << 4) & 0x3f]);  
                } else {  
                    int pos = (((a[bytePos] & 0x03) << 4) | ((a[bytePos + 1] & 0xf0) >> 4)) & 0x3f;  
                    toReturn.append(codec_table[pos]);  
                }  
                break;  
            default:  
                //never hanppen  
                break;  
            }  
            curPos+=6;  
        }  
        if(nn==2)  
        {  
            toReturn.append("==");  
        }  
        else if(nn==4)  
        {  
            toReturn.append("=");  
        }  
        return toReturn.toString();  
  
    }
    public static void main(String[] args) throws UnsupportedEncodingException {
		String s = "东营银行股份有限公司东城支行";
		byte[] bytes = encode(s.getBytes("UTF-8"));
		System.out.println(new String(bytes, "UTF-8"));
		
		byte[] bytesD = decode(bytes);
		System.out.println(new String(bytesD, "UTF-8"));
	}
}
